1. Field of the Invention
The present invention relates to a rear body structure of a vehicle having a pickup bed at the rear section, particularly for absorbing a collision impact from behind the vehicle.
2. Description of Prior Art
A rear body structure of a vehicle having a pickup bed at a rear section, convenient for cargo delivery, is disclosed in Japanese Un-examined Patent Publication No. 5-278643.
The pickup bed has an upwardly open space, and hence being an adverse structure in view of vehicle body strength. It is usually provided with a tailgate at the rearmost section for smooth cargo loading and unloading.
The pickup bed and its surrounding structure should bear a considerably heavy load such as a heavy cargo or an operator applied on the tailgate and also the pickup-bed rear section.
Such a vehicle requires countermeasures against a collision at the rear section to minimize deformation of the cabin for offering a driver with an enough space to survive when crushed and further to minimize deformation of door frames for rescue.
To meet such requirements, the pickup bed has to function as a crushable zone for absorbing collision impact.
Some vehicles have a monocoque body with a pickup bed, such as, disclosed in Japanese un-examined Patent Publication No. 5-27843. Also developed is a sedan-type vehicle having a monocoque body with a pickup bed at the rear section.
These types of the vehicle, however, require further improvements in vehicle body strength, particularly, in view of the collision from behind.
In view of the foregoing disadvantages, a purpose of the present invention is to provide a rear body structure of a vehicle having a pickup bed at the rear section with high vehicle body strength and high impact absorbing capability against the collision from behind.
The present invention provides a rear body structure of a vehicle having: a cabin; a pickup bed provided behind the cabin; a roof covering an upper section of the cabin; a pair of pillars provided at both rear ends of the cabin; a pair of side panels provided at both sides of the pickup bed from front ends of the pickup bed to the rear ends thereof, the rear body structure including: a pair of first reinforcement members provided from both edges of the roof to a front section of the pickup bed so that a front section of each first member lies along one of the edges of the roof while a rear section of each first member lies along one of the first pillars; a pair of second reinforcement members provided on upper edges of the side panels, each second reinforcement member being jointed, at a front end, to one of the first reinforcement members, each second reinforcement member being segmented into a first crushable zone and a second zone, the first crushable zone being located behind the second zone and being more fragile than the second zone against load applied from behind the vehicle; and a pair of third reinforcement members each provided from a lower edge of one of the side panels at the corresponding rear end of the pickup bed to a rear end of the second zone, in the vicinity of a front end of the first crushable zone.